Bitmapping is a method of representing digital data in the form of bits, that is to say binary values (0 or 1) . Bitmapping can be applied to different areas, such as images, sounds or fonts. In this article, we will look at bitmapping applied to sounds, and more particularly to playing audio CDs on the PS3.
What is the benefit of bitmapping for the PS3?
The PS3 is a gaming console that also allows you to play audio CDs, MP3 or AAC files, and stream them to an amplifier or speakers. To do this, the PS3 has several audio settings that influence sound quality. Among these settings is bitmapping.
Bitmapping adapts the digital audio signal to the resolution of the PS3's digital-to-analog converter (DAC) or amplifier. Indeed, the digital audio signal is made up of bits which represent the sound level at each moment. The number of bits per sample determines the resolution of the signal, that is to say its ability to reproduce sound nuances. The higher the resolution, the more faithful the sound to the original.
However, it is possible that the resolution of the digital audio signal does not correspond to that of the DAC which will convert it into an analog signal. For example, an audio CD has a resolution of 16 bits per sample, while the PS3's DAC has a resolution of 24 bits per sample. In this case, there is a mismatch between the number of bits in the signal and that of the DAC.
This is where bitmapping comes in. Bitmapping involves adding or removing bits from the digital audio signal to match the resolution of the DAC. There are several types of bitmapping:
Normal bitmapping
It adds zeros to the least significant bits of the digital audio signal so that it reaches the resolution of the DAC. For example, if the signal has a resolution of 16 bits and the DAC has a resolution of 24 bits, normal bitmapping will add 8 zeros to each sample. This type of bitmapping does not change the loudness of the signal, but it can introduce quantization noise.
Type 1 bitmapping
It adds random bits to the least significant bits of the digital audio signal so that it reaches the resolution of the DAC. For example, if the signal has a resolution of 16 bits and the DAC has a resolution of 24 bits, bitmapping type 1 will add 8 random bits to each sample. This type of bitmapping slightly changes the loudness of the signal, but it reduces quantization noise.
Type 2 bitmapping
It adds random bits to the least significant bits of the digital audio signal so that it reaches the resolution of the DAC, but it weights them according to the loudness of the signal. For example, if the signal has a resolution of 16 bits and the DAC has a resolution of 24 bits, type 2 bitmapping will add 8 random bits to each sample, but it will multiply them by a factor which depends on the sound level of the signal. This type of bitmapping slightly changes the loudness of the signal, but it reduces quantization noise even more.
The choice of bitmapping type depends on personal preference and the hardware used. Some prefer not to use bitmapping and leave the digital audio signal as is. Others prefer to use bitmapping type 1 or 2 to reduce quantization noise and improve sound quality. There is no universal rule, you have to test and listen to the result.
How to adjust bitmapping on PS3?
To adjust the bitmapping on the PS3, you must follow the following steps:
- Go to the PS3 Settings menu
- Select Audio Settings
- Select Digital Audio Output
- Choose the type of digital audio output depending on the cable used (HDMI, optical or AV)
- Select Sampling Rate
- Choose the sampling frequency depending on the type of audio source (44.1 kHz for audio CDs, 48 kHz for DVDs or games, 88.2 kHz or 176.4 kHz for high-resolution sources)
- Select Bitmapping
- Choose the type of bitmapping according to the DAC resolution (normal, type 1 or type 2)
There you go, you know everything about bitmapping and how to use it on the PS3. We hope this article was useful to you and that you enjoyed reading it. If you're a gamer with a passion for audio, you might also want to know what the best gaming headset stands are . These accessories allow you to store your headphones in an elegant and practical way, while protecting their earphones and cable. To discover our selection of the best gaming headset stands, click here. Please feel free to share your comments or questions with us.
